In response to my post below a friend emailed me the above sentence. As I suggest below it sounds crazy, and I don’t know if I believe it. But here’s an abstract from the Reich lab from June:

Estimating a date of mixture of ancestral South Asian populations

Linguistic and genetic studies have demonstrated that almost all groups in South Asia today descend from a mixture of two highly divergent populations: Ancestral North Indians (ANI) related to Central Asians, Middle Easterners and Europeans, and Ancestral South Indians (ASI) not related to any populations outside the Indian subcontinent. ANI and ASI have been estimated to have diverged from a common ancestor as much as 60,000 years ago, but the date of the ANI-ASI mixture is unknown. Here we analyze data from about 60 South Asian groups to estimate that major ANI-ASI mixture occurred 1,200-4,000 years ago. Some mixture may also be older—beyond the time we can query using admixture linkage disequilibrium—since it is universal throughout the subcontinent: present in every group speaking Indo-European or Dravidian languages, in all caste levels, and in primitive tribes. After the ANI-ASI mixture that occurred within the last four thousand years, a cultural shift led to widespread endogamy, decreasing the rate of additional mixture.

I freely admit that much of the conjecture here is above my pay-grade in terms of evaluation. But I do think it’s important think through. My “gut” tends to lean toward a “revenge of the Mesolithic” scenario promoted by some of Dienekes’ critics, but I don’t have a strong position.

I don’t know the answer to the question posted in title above, and I’m moderately skeptical that he has. But I wanted to give him full credit in the public record if researchers confirm his findings in the next few years. You can read the full post at his weblog, but basically he found that a West Asian modal element in a north British (Orkney) and Lithuanian individual seems to be negatively correlated with a Northwest European modal element and positively correlated with Near Eastern and South Asian components on a genomic level across different models in ADMIXTURE (e.g., does “South Asian” at K = 5 tend to match “West Asian” at K = 8).

But there is another component present in modern Europe, the West_Asian which is conspicuous in its absence in all the ancient samples so far. This component reaches its highest occurrence in the highlands of West Asia, from Anatolia and the Caucasus all the way to the Indian subcontinent. It is well represented in modern Europeans, reaching its minima in the Iberian peninsula….

Thanks to the public release of genetic data Dienekes has developed his theories in part out of his own analyses of said data. Though I’ve run fewer analyses, with smaller data sets, some of the same patterns jump out at me. In particular, there is a component which is modal in northern West Asia (e.g., the trans-Caucasian region) which seems to drop mysteriously between the French generally and French Basques, and the Basque vs. non-Basque Spanish samples. There are also similar, though not necessarily easy to map across the two regions, disjunctions in South Asia between geographically close Indian groups.

As must be obvious, I think now that the spread of Indo-European languages had some demographic impact. It wasn’t analogous to the spread of English to Jamaica, or the existence of French as an official language in Congo-Brazzaville. Because of this, I now believe it is possible in the near future that scientists will reconstruct the genome of the original Indo-Europeans. How?

1) Find the intersection of genetic segments on the chromosomal level which share identity-by-descent between widely separated Indo-European groups. For example, Greeks, Swedes, and Punjabis.

2) Check to see which of these intersecting elements is not found in nearby non-Indo-European groups. For example, Basques, Finns, and non-Brahmin South Indian Dravidian speakers. At least to an appreciable frequency.

My current supposition is that proportionally this component won’t be preponderant in most places, but, it will be significant. By reconstructing an Indo-European genome we may actually have the ability to ascertain the population’s urheimat, as we can compare its genetic distance to extant populations.

The image above is adapted from the 2010 paper A Predominantly Neolithic Origin for European Paternal Lineages, and it shows the frequencies of Y chromosomal haplogroup R1b1b2 across Europe. As you can see as you approach the Atlantic the frequency converges upon ~100%. Interestingly the fraction of R1b1b2 is highest among populations such as the Basque and the Welsh. This was taken by some researchers in the late 1990s and early 2000s as evidence that the Welsh adopted a Celtic language, prior to which they spoke a dialect distantly related to Basque. Additionally, the assumption was that the Basques were the ur-Europeans. Descendants of the Paleolithic populations of the continent both biologically and culturally, so that the peculiar aspects of the Basque language were attributed by some to its ancient Stone Age origins.

As indicated by the title the above paper overturned such assumptions, and rather implied that the origin of R1b1b2 haplogroup was in the Near East, and associated with the expansion of Middle Eastern farmers from the eastern Mediterranean toward western Europe ~10,000 years ago. Instead of the high frequency of R1b1b2 being a confident peg for the dominance of Paleolithic rootedness of contemporary Europeans, as well as the spread of farming mostly though cultural diffusion, now it had become a lynch pin for the case that Europe had seen one, and perhaps more than one, demographic revolutions over the past 10,000 years.

This is made very evident in the results from ancient DNA, which are hard to superimpose upon a simplistic model of a two way admixture between a Paleolithic substrate and a Neolithic overlay. Rather, it may be that there were multiple pulses into a European cul-de-sac since the rise of agriculture from different starting points. We need to be careful of overly broad pronouncements at this point, because as they say this is a “developing” area. But, I want to go back to the western European fringe for a moment.

In this book I have offered a synthesis of genetic and other evidence. Everything points to a single southern exodus from Eritrea to the Yemen, and to all the non-African male and female gene lines having arisen from their respective single out-of-Africa founder lines in South Asian (or at least near the southern exit). I regard the genetic logic for this synthesis as a solid foundation, and I have based the rest of my reconstruction of the human diaspora upon it. Obviously, the ‘choice’ of starting point (mine or theirs) determined all the subsequent routes our ancestors and cousins took. Tracing the onward trails is only possible as a result of marked specificity in regional distribution of the genetic branches The geographic clarity of both male and female gene trees is a big departure from the fuzzy inter-regional picture shown by older genetic studies. The degree of segregation of lines into different countries and continents is in itself good evidence that once they got to their chosen new homes, the pioneers generally stayed put, at least until the Last Glacial maximum forced some of them to move. This conservative aspect of our genetic prehistory also provides a partial explanation for the fact that when we look at a person, we can usually tell, to the continent, where their immediate ancestors came from, and underlies differences that some of us still call ‘race.’

Oppenheimer wrote the above in the early aughts, as his book was published in 2003. Much of this is generally in line with the ‘orthodoxy’ of the day. I believe that Oppenheimer’s assertion that there was one southern migration out of Africa by anatomically modern humans has gained some advantage over the alternative model of two routes, northern and southern, over the past ten years (Spencer Wells’ The Journey of Man sketches out the two wave model). Other assertions and assumptions have not stood the test of time. In particular, I would contend that generally the ‘conservative aspect of our genetic prehistory’ can no longer be taken for granted. Specifically, it seems likely now that much occurred after the Ice Age and during the Neolithic.

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